As my collection of RE Super/Super D camera bodies grew, I noted that the pattern of scribed lines on the mirror were not consistent. I originally supposed that Topcon phased in different patterns as part of product improvement over the life of production. However, when I began correlating patterns with serial numbers there was no correlation. So why did they use at least seven different styles? You can understand my consternation by looking at the figure below showing the different patterns I have examined.

The light sensitive element (CdS cell) is comprised of two different circuits--one for low light levels and one for high light levels. The sensitive part of the cell is placed in the four corners where the scribed pattern is fine--note that in this area the pattern is always the same. The less sensitive portion is confined to the center cross where  the variations occur.
My present theory is that manufacturing tolerances produced variations in sensitivity of the CdS, not only from cell to cell but also between the two circuits on a single cell. During production, components in the galvanometer circuit could be selected to compensate for differences cell to cell and were adjusted to calibrate the high sensitive element. The low sensitive element could then be matched by adjusting the amount of light allowed to reach that element--fewer scribe marks to reduce sensitivity and more to increase it. Thus, the mirror pattern was matched to characteristics of each cell during assembly of the CdS cell-mirror combination.

On the rear plate of every RE Auto lens there is an extra pin whose function is unknown, at least to me. This pin is present on every lens I own from the earliest (serial number 46) to the last lens produced by Topcon, the two GNs. On two of my lenses the pin is missing--the threaded hole for the pin is there--and they work fine on all models of the camera.
Note that this extra pin is on the same radius as the Lens Locking pin, but separated by approximately 43 degrees.
One suggestion I have received is that the pin was provided to allow the lens to be mounted on an unknown type of camera,. But since my knowledge of other camera makes is limited I do not know. OK all you camera buffs, do any of you know of a camera that accepts a standard Exakta bayonet mount but has the lens locking catch in a different position?

The instruction books for the RE Super/Super D cameras show a chrome version of the 6.5X High Magnification Viewfinder. The figure below is from one such book, probably dated sometime around 1969. The viewfinder is definitely in chrome finish with a black stripe for the Topcon name. Even the cap seem to have a chrome finish. Strange though, the rubber eyecup at the top of the finder is a light color (gray) rather than the normal black.

I have never seen this viewfinder in any finish but black and neither has anyone I have had input from. My Beseler literature shows only black (of course with their logo above Topcon).

I assume the chrome model was a prototype and never went into production, but things like this perplex us collectors, making us wonder if we are missing a rare item.

When Topcon brought out the their big gun lens, the 300 mm f/2.8, in 1957 they accompanied it with a shorter, but even faster, little brother. This shorter lens was the R Topcor 135 mm f2 with preset aperture control. What I find curious about this lens is that while the big 300 mm was listed in all instruction books for the RE Super/Super D, from 1963 to the end, the 135 never appeared in any Topcon publications. And yet Beseler advertised this lens as late as 1969. The image shown is taken from a Beseler brochure of this date, BESELER TOPCON ACCESSORIES.

So what is going on? Did Beseler stock up on these lenses before the advent of the Super D and was trying to empty their warehouse on buyers of the new camera?